The wristwatch market at the present time is moving strongly in the direction of the battery-powered type which uses a quartz crystal oscillator as a time-standard. The accuracy of such watches is far superior to the accuracy of watches depending upon the mechanical movement of one type or another. The driving energy of such wristwatches is supplied by an electro-chemical cell or a battery, depending upon the voltage necessary to drive both the circuitry and the display means.
In order to avoid the need for changing the battery or cell with a frequency sufficiently great as to make such wristwatches appear unreliable and bothersome, a silver oxide battery is generally used because such batteries provide a maximum in stored energy. However, since it is desired to make such watches as small as possible, particularly where the watch is to be worn by a woman, the capacity of the battery must similarly be restricted. Consequently it has not been possible to design such watches to accept a battery which will provide the necessary power for longer than a period of a year or two. This problem has been met by incorporating a solar battery in the wristwatch for recharging the electro-chemical battery, it obviously being necessary to use a rechargeable, i.e., a storage battery rather than a primary, the latter being the type used in the absence of a solar battery.
Although the incorporation of a solar battery has eliminated the necessity for periodic replacement of the electro-chemical battery, the full benefit of the solar battery has not as yet been made available, due to the fact that the support structures and connecting portions of the circuitry have been relatively primitive. As is evident, it would be highly desirable to make available designs which minimize space requirements and which, at the same time, provide complete reliability with respect to electrical connection. In addition, the design should be suitable for mass production at as low a cost as possible.